In the restaurant industry, there are a relatively few methods for filtering and cleaning cooking oil. Most commonly, the cooking oil is pumped out of the fryer through a hose and is then passed through a filter supported by a screen. The cooking oil passes through the filter into a tank, while the waste is collected by the filter. The cooking oil is then returned to the fryer. To achieve this, the tank for receiving the cooking oil and the pump are often positioned on a cart, which can be moved next to the fryer for the filtering/cleaning process. However, the hot cooking oil is often exposed and presents a safety hazard to the employees in the vicinity of the fryer. Furthermore, in using such a system, the pump may slow as the filter collects waste and may occasionally stop moving the cooking oil. In that case, the filter media paper must then be removed and disposed of by hand, which creates another safety hazard.
In another method for filtering and cleaning cooking oil, the fryer includes a drain valve that is opened to expel the cooking oil through a cone-shaped paper filter supported by a wire mesh screen. The cooking oil passes through the filter into a pot or similar vessel, while the waste is collected by the filter. The cooking oil in the pot must then be poured back into the fryer, which is not only time-consuming, but presents another significant safety hazard.
Finally, in view of the attendant safety hazards, some restaurants do not filter and clean the cooking oil, but rather simply discard and replace the cooking oil when it becomes too dirty.